As Andy Murray can confirm, growing up is hard to do. The 19-year-old Scot was well placed to claim a significant victory here yesterday when his growing body failed him once again.
Murray led Gaël Monfils, another of the game's most promising teenagers, by two sets to one in the first round of the French Open before an injury to his lower back scuppered his chances of beating the No 25 seed. Monfils, who had lost when they met in Hamburg a fortnight ago, won 6-4, 6-7, 1-6, 6-2, 6-1 in three hours and 42 minutes.
The British No 2 was serving at 5-2 in the second set tie-break when he felt his back go. He won both the tie-break and the third set but called for the trainer as the problem worsened. By the end he was serving well below full pace and struggled whenever stretching to play a groundstroke.
"My back feels really tight and tired," Murray said afterwards. "There was no strength there. When I was moving wide I just couldn't do it. I felt as though my back was going to collapse all the time." Even so, it was a match - played in squally showers and a bitingly cold wind - that Murray felt he should have won quite comfortably. He led 3-0 in the first set but then lost five games in a row.
Despite his back problem, the Scot won the third set at a canter as a nervous Monfils imploded. When the Parisian started querying line calls - "I was a little bit disappointed with him," Murray said later - even his home crowd started to jeer. Murray won the first game of the fourth set but lost 12 of the next 14 as his back quickly deteriorated.
There had been some splendid tennis in the second set. Monfils, eight months older than Murray, hit some thunderous forehands and retrieved numerous lost causes thanks to his long reach and speed around the court. Murray had to be at his inventive best, varying the pace and playing some delightful drop shots.
However, losing matches from a winning position because of physical problems has become an all too familiar soundtrack to Murray's life story in the last year. Cramp was a key factor in his defeats to Thomas Johansson at Queen's, David Nalbandian at Wimbledon and Jean-René Lisnard in Monte Carlo. In March he suffered an ankle injury while losing to Stanislas Wawrinka in Miami.
Murray has consulted a German doctor, who says the root of his problems is the fact that he is still growing. The cramping in particular might be caused by the fact that the lower part of his spine is still growing.
"The doctor said that practising in Spain a lot and playing on clay was why I hadn't fully grown," Murray said. "The ball bounces really high all the time and there's a lot of lunging, which takes its toll on the back. This is my sixth or seventh week on clay. The long rallies today didn't help either." He added: "It's really difficult to get yourself in the best shape until you stop growing because you can get injuries. Obviously when you have a slight weakness in your lower back because you're still growing you can't push too hard or you'll hurt yourself.
"I hope I'm going to stop growing at the end of this year so I can really get myself in my best shape. I'm just over 6ft 2in now. That's a pretty good height for a tennis player." Murray does not expect the injury to affect his grass-court campaign, which is due to begin at Queen's the week after next. "The grass is pretty soft so it doesn't put too much strain on your body. I think I've got enough time to see the physio, get a lot of massage and do some exercises."
Andy Roddick, the men's No 5 seed, and Nadia Petrova, the women's No 3 seed, were also in the wars. Roddick aggravated an ankle injury and retired when two sets down to Alberto Martin, and Petrova, one of the year's form players, won only four games against Akiko Morigami.
Justine Henin-Hardenne, the defending women's champion, beat Maret Ani 6-3, 6-0, while Martina Hingis, playing her first match here for five years, beat Lisa Raymond, 6-2, 6-2.
Brits in Paris: How they fared
First round: beat Kenneth Carlsen (Den) 6-3, 6-4, 4-6, 6-4 on Sunday.
Second round: v Dmitri Tursunov (Rus), today.
First round: Britain's No 2, hampered by a back injury, lost to Gaël Monfils (Fr) 6-4, 6-7, 1-6, 6-2, 6-1 yesterday.
First round: lost to Paul Capdeville (Chile) 3-6, 1-6, 6-4, 6-7 on Monday.